Field scale spatial variability of rice grain and DTPA-micronutrients

摘要

Rice grain is one of the major sources of micronutrient input for human health in southern part of China. The imforrnation about their concentration and spatial variability is helpful for nutritional study and agronomic management. This investigation was performed in Deqing County, Zhejiang Province, China. The main objectives were to determine the concentration of micronutrients and characterize their spatial variability in rice grain and soil diethylenetriamine pentaacetic acid (DTPA) extracts, as well as quantify their relationships with major soil properties. Classical statistics and geostatistics were used for data analysis. Significant correlation existed between concentrations in DTPA-extracts and rice grain. Experimental semivariograms were developed, fitted with spherical models. Semivariance analysis showed that the pH and micronutrients in rice grain had a moderate spatial depend ence, whereas organic matter and DTPA micronutrient concentrations had strong spatial dependence. The spatial distribution of the different variables was estimated by kriging. Maps were generated that were useful to identify the micronutrients status, monitor variability of major soil properties, and develop agronomic management practices at field scale.